Alert archive / Illinois / Tornado Warnings in 2017

Tornado Warning 2, NWS Chicago, IL

February 28, 2017Grundy County, Kendall County, LaSalle County, Illinois

NWS Chicago, IL issued this tornado warning at Feb 28, 2017, 4:51 PM CST for Grundy County, Kendall County, LaSalle County, Illinois. It was in force for 39 min. 4 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Feb 28, 2017, 4:51 PM CST (22:51 UTC)
Expired: Feb 28, 2017, 5:30 PM CST
In force: 39 min
Issued by: NWS Chicago, IL
Area: Storm-based polygon
Tornado: Observed
Damage threat: Considerable
Hail: 1.75 in

Counties Grundy County, IL, Kendall County, IL, LaSalle County, IL

What was reported inside it

Time	Report	Where	Remark
Feb 28, 5:00 PM CST	TORNADO	3 N Marseilles, IL	UPDATED FOR NWS STORM SURVEY INFORMATION. LOCATION AND TIME IS OF START OF TORNADO. THE MAXIMUM INTENSITY IS EF-1 WITH ESTIMATED PEAK WINDS OF 110 MPH. THE PATH LENGTH WAS 1.5 MILES.
Feb 28, 5:06 PM CST	TORNADO	Marseilles, IL	AT THE INTERSECTION OF NE 30TH AND E 25TH. ELECTRICAL TOWER DOWN AND MULTIPLE BULDINGS DAMAGED.
Feb 28, 5:06 PM CST	TORNADO	Marseilles, IL	AT THE INTERSECTION OF NE 30TH AND E 25TH. ELECTRICAL TOWER DOWN BLOCKING ROAD AND MULTIPLE BULDINGS DAMAGED. HOUSE WITH ROOF BLOWN OFF. POWER LINE DOWN ON ROAD.
Feb 28, 5:13 PM CST	TORNADO	2 Nw Morris, IL	STORM CHASER REPORTS VERY LARGE TORNADO 2 MILES NORTHWEST OF MORRIS.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Feb 28, 2:57 PM CST	Tornado Watch	SPC	7 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 10.9 hours before the alert went out and 136 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 569 m above ground
0-6 km bulk shear: 67 kt
0-1 km storm-relative helicity: 276 m²/s²
0-3 km storm-relative helicity: 285 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

302 
WFUS53 KLOT 282251
TORLOT
ILC063-093-099-282330-
/O.NEW.KLOT.TO.W.0002.170228T2251Z-170228T2330Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Chicago/Romeoville Il
451 PM CST TUE FEB 28 2017

The National Weather Service in Chicago has issued a

* Tornado Warning for...
  Southern Kendall County in northeastern Illinois...
  East central La Salle County in north central Illinois...
  Northern Grundy County in northeastern Illinois...

* Until 530 PM CST

* At 450 PM CST, a confirmed large and extremely dangerous tornado
  was located over Ottawa, moving east at 45 mph.

  This is a PARTICULARLY DANGEROUS SITUATION. TAKE COVER NOW! 

  HAZARD...Damaging tornado. 

  SOURCE...Weather spotters confirmed tornado. 

  IMPACT...You are in a life-threatening situation. Flying debris 
           may be deadly to those caught without shelter. Mobile 
           homes will be destroyed. Considerable damage to homes, 
           businesses, and vehicles is likely and complete 
           destruction is possible. 

* The tornado will be near...
  Marseilles around 455 PM CST. 
  Seneca around 505 PM CST. 
  Morris around 520 PM CST. 
  Channahon and Minooka around 530 PM CST. 

Other locations impacted by this tornadic thunderstorm include Carbon
Hill and Lisbon.

This includes...  Gebhard Woods State Park, Grundy County Speedway
and Fairgrounds, Illini State Park, and William G Stratton State
Park.
 
Including the following interstate...
 I-80 between mile markers 93 and 121.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

To repeat, a large, extremely dangerous and potentially deadly
tornado is on the ground. To protect your life, TAKE COVER NOW! Move
to a basement or an interior room on the lowest floor of a sturdy
building. Avoid windows. If you are outdoors, in a mobile home, or in
a vehicle, move to the closest substantial shelter and protect
yourself from flying debris.

Heavy rainfall may hide this tornado. Do not wait to see or hear the
tornado. TAKE COVER NOW!

&&

LAT...LON 4129 8879 4142 8880 4160 8829 4126 8826
TIME...MOT...LOC 2250Z 257DEG 39KT 4135 8880 

TORNADO...OBSERVED
TORNADO DAMAGE THREAT...CONSIDERABLE
HAIL...1.75IN

$$

BMD

3 follow-up statements

121 
WWUS53 KLOT 282304
SVSLOT

Severe Weather Statement
National Weather Service Chicago/Romeoville Il
504 PM CST TUE FEB 28 2017

ILC063-093-099-282330-
/O.CON.KLOT.TO.W.0002.000000T0000Z-170228T2330Z/
Kendall IL-La Salle IL-Grundy IL-
504 PM CST TUE FEB 28 2017

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 530 PM CST FOR SOUTHERN
KENDALL...EAST CENTRAL LA SALLE AND NORTHERN GRUNDY COUNTIES...
    
At 504 PM CST, a confirmed large and extremely dangerous tornado was
located over Marseilles, moving east at 35 mph.

This is a PARTICULARLY DANGEROUS SITUATION. TAKE COVER NOW!

HAZARD...Damaging tornado. 

SOURCE...Weather spotters confirmed tornado. 

IMPACT...You are in a life-threatening situation. Flying debris may 
         be deadly to those caught without shelter. Mobile homes 
         will be destroyed. Considerable damage to homes, 
         businesses, and vehicles is likely and complete destruction 
         is possible. 

The tornado will be near...
  Morris around 525 PM CST. 
  Minooka around 530 PM CST. 

Other locations impacted by this tornadic thunderstorm include Carbon
Hill and Lisbon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Heavy rainfall may hide this tornado. Do not wait to see or hear the
tornado. TAKE COVER NOW!

&&

LAT...LON 4130 8877 4141 8878 4160 8829 4126 8826
TIME...MOT...LOC 2304Z 262DEG 31KT 4136 8868 

TORNADO...OBSERVED
TORNADO DAMAGE THREAT...CONSIDERABLE
HAIL...1.75IN

$$

BMD

814 
WWUS53 KLOT 282318
SVSLOT

Severe Weather Statement
National Weather Service Chicago/Romeoville Il
518 PM CST TUE FEB 28 2017

ILC099-282327-
/O.CAN.KLOT.TO.W.0002.000000T0000Z-170228T2330Z/
La Salle IL-
518 PM CST TUE FEB 28 2017

...THE TORNADO WARNING FOR EAST CENTRAL LA SALLE COUNTY IS
CANCELLED...
    
The tornadic thunderstorm which prompted the warning has moved out 
of the warned area. Therefore, the warning has been cancelled. A 
severe thunderstorm warning has been issued for two new 
thunderstorms that developed west of the initial warned storm.

A tornado watch remains in effect until 1000 PM CST for northeastern
Illinois.

LAT...LON 4134 8858 4144 8859 4160 8829 4131 8826
TIME...MOT...LOC 2317Z 254DEG 38KT 4143 8849 

$$

ILC063-093-282330-
/O.CON.KLOT.TO.W.0002.000000T0000Z-170228T2330Z/
Kendall IL-Grundy IL-
518 PM CST TUE FEB 28 2017

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 530 PM CST FOR
SOUTHEASTERN KENDALL AND NORTHERN GRUNDY COUNTIES...
    
At 517 PM CST, a confirmed large and extremely dangerous tornado was
located north of Morris, moving east at 45 mph.

This is a PARTICULARLY DANGEROUS SITUATION. TAKE COVER NOW!

HAZARD...Damaging tornado. 

SOURCE...Weather spotters confirmed tornado. 

IMPACT...You are in a life-threatening situation. Flying debris may 
         be deadly to those caught without shelter. Mobile homes 
         will be destroyed. Considerable damage to homes, 
         businesses, and vehicles is likely and complete destruction 
         is possible. 

The tornado will be near...
  Morris around 520 PM CST. 
  Channahon and Minooka around 530 PM CST. 

Other locations impacted by this tornadic thunderstorm include
Lisbon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Heavy rainfall may hide this tornado. Do not wait to see or hear the
tornado. TAKE COVER NOW!

&&

LAT...LON 4134 8858 4144 8859 4160 8829 4131 8826
TIME...MOT...LOC 2317Z 254DEG 38KT 4143 8849 

TORNADO...OBSERVED
TORNADO DAMAGE THREAT...CONSIDERABLE
HAIL...1.75IN

$$

BMD

135 
WWUS53 KLOT 282331
SVSLOT

Severe Weather Statement
National Weather Service Chicago/Romeoville Il
531 PM CST TUE FEB 28 2017

ILC063-093-282340-
/O.EXP.KLOT.TO.W.0002.000000T0000Z-170228T2330Z/
Kendall IL-Grundy IL-
531 PM CST TUE FEB 28 2017

...THE TORNADO WARNING FOR SOUTHEASTERN KENDALL AND NORTHERN GRUNDY
COUNTIES HAS EXPIRED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer appears capable of producing a tornado.
Therefore the tornado warning has been allowed to expire.  However 
large hail and damaging winds are still possible with this 
thunderstorm.

A tornado watch remains in effect until 1000 PM CST for northeastern
Illinois.

Remember, a Severe Thunderstorm Warning still remains in effect for 
northeastern Grundy and southeastern Kendall counties.

LAT...LON 4134 8858 4144 8859 4160 8829 4131 8826
TIME...MOT...LOC 2330Z 257DEG 39KT 4146 8833 

$$

BMD

The office that day

Everything else NWS Chicago, IL issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Feb 28, 3:48 AM CST	Gale Watch	LOT		11 hr
Feb 28, 3:48 AM CST	Small Craft Advisory	LOT		24 hr
Feb 28, 8:27 AM CST	River Flood Advisory	LOT	Will	36 hr
Feb 28, 10:17 AM CST	River Flood Advisory	LOT	LaSalle	5 days
Feb 28, 10:17 AM CST	River Flood Advisory	LOT	Bureau, LaSalle, Putnam	5 days
Feb 28, 3:07 PM CST	Gale Warning	LOT		33 hr
Feb 28, 3:07 PM CST	Small Craft Advisory	LOT		43 hr
Feb 28, 4:14 PM CST	Severe Thunderstorm Warning	LOT	LaSalle	46 min
Feb 28, 4:27 PM CST	Tornado Warning	LOT	LaSalle	48 min
Feb 28, 4:41 PM CST	Severe Thunderstorm Warning	LOT	Lee, Ogle	34 min
Feb 28, 5:13 PM CST	Severe Thunderstorm Warning	LOT	LaSalle	47 min
Feb 28, 5:15 PM CST	Severe Thunderstorm Warning	LOT	DeKalb, Lee, Ogle	45 min
Feb 28, 5:28 PM CST	Severe Thunderstorm Warning	LOT	Grundy, Kendall, Will	47 min
Feb 28, 5:36 PM CST	Tornado Warning	LOT	LaSalle, Livingston	39 min
Feb 28, 5:51 PM CST	Severe Thunderstorm Warning	LOT	Cook, DeKalb, DuPage, Kane, Lake, McHenry	39 min
Feb 28, 5:53 PM CST	Special Marine Warning	LOT		2 hr

Nearby

Tornado Warnings in Illinois, 2017 Every tornado warning in 2017 Tornadoes in 2017

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive.